You guys are going to have a blast! In early January, three of us rode for a week through Mexico - all on-road. We spent two nights in Jalpan and really enjoyed the area. Have been lurking on the sidelines since before our trip to Mexico. Recent entries/questions about radios prompted me to jump in and share my experience with that technology.
Guess I'm considered a geek. My '05 RT had a Kenwood D700 50 watt ham radio, a CB radio, and an FRS radio all controlled from a single PTT to an Autocom system driving sound to my helmet. On the '13 RT I switched to the Sena system. Used the SMH10 on my helmet and had the bike's radio system output GPS signals and stereo music via the Sena SM10 module to my helmet. Used the Sena SR10 module to collect Valentine V1 radar detector and Kenwood FRS radio signals for transmission to my helmet.
Encountered a lot of ground-loop issues with the SR10 until Sena replaced it with a new one. The Kenwood TK3101 FRS radio was nice in that it had a removable antenna. This enabled me to mount a blade/stealth antenna vertically outside along the rear fender while the unit itself was under the seat. The entire setup was bike-powered. At night I only had to charge the Sena SMH10 on my helmet. Then I sold the RT.
For the GSA, I upgraded to the Sena 20S and bought the Motorola MUR350 Bluetooth FRS radio. After pairing the radio to the Sena 20S, I was able to communicate with my wife who was inside the house on a handheld FRS radio. The radio was mounted on the left mirror stalk because, as mentioned by others, there is no practical, inexpensive remote PTT solution for that radio. Have not tested that radio on a ride but the COFSTA group of riders in North Carolina recommend that radio to their members.
Real life issues with bike-to-bike communication:
* A motorcycle is an extremely hostile environment for radio communication! Lots of signal interference.
* Transmission distance is a function of the power output/antenna efficiency, signal frequency, and terrain.
** Power output/Antenna Efficiency
FRS radios are limited by the FCC to 0.5 watt output. However, most, if not all, FRS radios also cover a number of GMRS channels and seven of those channels are shared. Hand held GMRS radios are permitted to output up to 5 watts, so you can buy the Midland GXT1000 FRS/GMRS radio and transmit up to 5 watts! Blister-pack radios all have rubber-ducky antennas. This means you need to mount the radio as high as you can on your bike. Bluetooth Class 1 radios (Sena 20S) have a power output of 0.1 watts and a maximum range of 100 meters (330 feet).
** Signal frequency:
The lower the signal frequency the longer the transmission range, assuming the same effective power output. However, the lower the signal frequency, the longer the required antenna length. So what are the common frequencies we might see for motorcycle communications?
CB - 27 megaHertz - AM signals - prone to interference.
Ham radio (2 meter) - 150 megaHertz - FM signals - low interference.
FRS/GMRS radio - 462 megaHertz - FM signals - low interference.
Sena (Bluetooth)- 2,400 megaHertz - Frequency hopping spread spectrum - low interference.
** Terrain/Obstructions:
Marketing brochures for FRS/GMRS radios make outlandish claims which are theoretically correct, e.g., 35 mile range - (from one mountain top to the next one!) In the real world, the signal is only good for radio-signal line-of-sight applications. Yet, if there are many metal objects (e.g., cars, trucks) or buildings around, the signal will scatter and can "reach around corners"! Personally experienced good FRS reception within a city from another rider who was at least a block away on a side street - i.e., not visible from where I was located. Sena achieves its 20S range claims by requiring a specific pairing order. That scheme allows signal transmission to approach 2000 meters. However, if two riders in the net switch places, e.g., after a stop, the paired connections may break and leave some riders "out in the cold." So, while the Sena approach offers many advantages, the FRS/GMRS radio provides the most effective bike-to-bike solution because the typical power output is 5x to 50x greater than Bluetooth and is not restricted by pairing.
Hope this helps to answer some of the questions posed by previous posters.
Herman
P.S. Look forward to many pictures and stories about your ventures next April!